Assessment and management of shellfish resources

Context

To support the effective management and potential exploitation of marine resources, AZTI has been assessing the status of different coastal resources for many years.

The project currently focuses on five main resources:

• Grooved carpet shell clam (Ruditapes decussatus) and common cockle (Cerastoderma edule), found in the Oka, Butroe and Bidasoa estuaries.
• Goose barnacle (Pollicipes pollicipes), whose distribution and biomass are linked to wave energy and which is assessed along the entire Basque coast.
• Sea urchin (Paracentrotus lividus), a species monitored since 2007, with new surveys planned between Cape Billano (Gorliz) and Algorta.
• The red alga Gelidium corneum, traditionally harvested along the Basque coast and currently monitored to maintain the historical data series and assess its potential recovery.

The project forms part of the data collection section of Spain’s Operational Programme under Article 77 of the European Maritime and Fisheries Fund (EMFF), within Activity No. 27 (“Biological variables”). This work strengthens the system for collecting the biological, environmental, technical and socio-economic data required to ensure the sustainable exploitation of living marine resources.

In this way, the project contributes to improving knowledge and management of coastal ecosystems in the Basque Country, providing essential scientific information to support decision-making and the development of adaptive management plans.

Objectives

The overall aim of the project is to collect and analyse the biological samples required to assess the status of the main shellfish resources along the Basque coast, ensuring their sustainable management through a robust and continuous scientific evidence base.

The specific objectives include:

• Sampling bivalve molluscs (clams and cockles) in the Butroe, Oka and Bidasoa estuaries, during summer and winter surveys.
• Sampling goose barnacles along the entire Basque coast and specifically in the Bakio–Cape Billano area.
• Sampling sea urchins along the coastal stretch between Cape Billano (Gorliz) and Algorta.
• Sampling the red alga Gelidium corneum between Orio and Hondarribia, in order to maintain the historical data series and analyse its evolution.

These surveys will provide up-to-date biological material that is essential for assessing the biomass, coverage and level of exploitation of each resource, as well as their interannual variability.

Expected impact

The information generated will help improve the management and conservation of shellfish resources in the Basque Country, supporting their long-term sustainable exploitation.

In particular, the project is expected to:

1. Improve management decisions on catch quotas and harvesting areas by providing up-to-date scientific data.
2. Conserve and enhance resource productivity through rational exploitation adapted to the capacity of populations to replenish themselves.
3. Contribute to the conservation of coastal ecosystems and to the sustainability of the Basque fishing and shellfish sectors.
4. Provide reference information for future assessments and fisheries and environmental management policies.

Funding